It is commonly known that water wave action creates a washout of sand and stone at a beach, and there is an erosion problem where the beachline can actually be receding toward the land. The prior art has various configurations of block which is intended to dissipate the wave energy and to reduce the beach material from washing further into the body of water. Blocks of the prior art generally have two functions, one is to dissipate the energy or force of the wave by permitting water to flow through the block, and another is to endeavor to stop the wave flow entirely by blocking the wave with a substantially solid block
With regard to permitting the wave to flow through the block, U.S. Pat. Nos. 3,386,250 and 4,129,006 and 4,367,978 and 4,431,337 all show blocks with openings therethrough. However, in that form of block, the water can also reverse flow and move in the seaward direction after it has initially passed the block in the landward direction. In that in-and-out type of flow, the water may be reduced in its wave energy, but the sand and the like which forms a beach is not controlled and it too will be flowing generally outwardly to erode the beach.
In the present invention, the block is designed to actually build a beach, rather than simply endeavor to retard the flow of the wave, and, in the present invention, the sand is deposited behind a row of the blocks to enhance the size of the beach. To accomplish this, the present invention differs from the prior art in that it dissipates the energy of the wave moving landward, but it also serves to have the sand fall out from the wave and thus build the beach. The aforementioned patents are arranged to have the water, and therefore the sand, flow readily and easily in both directions, so that the beach is not actually built or increased in sand, but, it is instead the purpose of the block to simply reduce the energy of the incoming wave. The present invention also accomplishes the desirable effect of reducing the incoming wave energy, but, as mentioned, there is the additional feature of building the size of the beach itself.
Still further, the blocks of the present invention differ from the prior art in that they are susceptible to being positioned in a line in side-by-side relationship and interlocked block-to-block so that the line of blocks is stable and the movement of the water therethrough or thereover will not move the blocks out of line. In conjunction with that stability of the line of blocks, the block of the present invention has the feature of permitting the wave to flow therethrough in a manner which will actually enhance the stability of the position of the block, and the block also has a front toe feature for stability and it has side walls for presenting resistance to a wave directed angularly at the block. All of these several features therefore combine to provide a block which is stable and which can be positioned in a side-by-side relationship to form a line of blocks which will retain their aligned position and thus retard the force of the incoming flow of water and will actually build the beach through the deposit of sand washing toward the shoreline from the body of water.